US20180004101A1 - Single-layer type electrophotographic photoreceptor for positive charging, electrophotographic photoreceptor cartridge, and image forming apparatus - Google Patents

Single-layer type electrophotographic photoreceptor for positive charging, electrophotographic photoreceptor cartridge, and image forming apparatus Download PDF

Info

Publication number
US20180004101A1
US20180004101A1 US15/702,494 US201715702494A US2018004101A1 US 20180004101 A1 US20180004101 A1 US 20180004101A1 US 201715702494 A US201715702494 A US 201715702494A US 2018004101 A1 US2018004101 A1 US 2018004101A1
Authority
US
United States
Prior art keywords
electrophotographic photoreceptor
group
formula
photoreceptor
mass
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US15/702,494
Other languages
English (en)
Inventor
Mitsuo Wada
Hiroe Fuchigami
Akira Ando
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Chemical Corp
Original Assignee
Mitsubishi Chemical Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Chemical Corp filed Critical Mitsubishi Chemical Corp
Assigned to MITSUBISHI CHEMICAL CORPORATION reassignment MITSUBISHI CHEMICAL CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ANDO, AKIRA, FUCHIGAMI, HIROE, WADA, MITSUO
Publication of US20180004101A1 publication Critical patent/US20180004101A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0601—Acyclic or carbocyclic compounds
    • G03G5/0609—Acyclic or carbocyclic compounds containing oxygen
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/75—Details relating to xerographic drum, band or plate, e.g. replacing, testing
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/75—Details relating to xerographic drum, band or plate, e.g. replacing, testing
    • G03G15/751—Details relating to xerographic drum, band or plate, e.g. replacing, testing relating to drum
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0503—Inert supplements
    • G03G5/051—Organic non-macromolecular compounds
    • G03G5/0517—Organic non-macromolecular compounds comprising one or more cyclic groups consisting of carbon-atoms only
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
    • G03G5/0528—Macromolecular bonding materials
    • G03G5/0557—Macromolecular bonding materials obtained otherwise than by reactions only involving carbon-to-carbon unsatured bonds
    • G03G5/0564—Polycarbonates
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0601—Acyclic or carbocyclic compounds
    • G03G5/0605—Carbocyclic compounds
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0601—Acyclic or carbocyclic compounds
    • G03G5/0618—Acyclic or carbocyclic compounds containing oxygen and nitrogen
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0622—Heterocyclic compounds
    • G03G5/0624—Heterocyclic compounds containing one hetero ring
    • G03G5/0627—Heterocyclic compounds containing one hetero ring being five-membered
    • G03G5/0631—Heterocyclic compounds containing one hetero ring being five-membered containing two hetero atoms
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0664—Dyes
    • G03G5/0675—Azo dyes
    • G03G5/0677—Monoazo dyes
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02—Charge-receiving layers
    • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0664—Dyes
    • G03G5/0696—Phthalocyanines

Definitions

  • Electrophotography has been widely used in the field of copiers and in the field of various printers, because of the advantages such as instantaneousness, the ability to produce high-quality images, and the like.
  • electrophotographic photoreceptors (hereinafter, simply also referred to as “photoreceptor”), which are the core of electrophotography, photoreceptors employing, as the photoconductive substance thereof, an organic photoconductive substance having advantages such as non-pollution, ease of film formation, and ease of production has been used in recent years.
  • a so-called function allocation type photoreceptor in which different compounds are separately in charge of charge generation and charge transport, can be made of various materials and has easily controllable photoreceptor properties. This has made the development of such function-allocation type photoreceptor the mainstream of the photoreceptor development.
  • single-layer type electrophotographic photoreceptor hereinafter, referred to as “single-layer type photoreceptor”
  • multilayer type electrophotographic photoreceptor hereinafter, referred to as “multilayer type photoreceptor”: the former is a photoreceptor that contains a charge generation material and a charge transport material within the same layer; and the latter is a photoreceptor in which separate layers (charge generation layer and charge transport layer) each including the charge generation material and the charge transport material respectively are laminated.
  • the multilayer photoreceptor is a photoreceptor in which the function of each layer can be easily optimized and the characteristics thereof are also easily controlled, and thus, most of the current photoreceptors are of this type.
  • the multilayer type photoreceptor includes a charge generation layer and a charge transport layer disposed on a substrate in this order.
  • charge transport layer there are extremely few materials suitable for an electron transport material, whereas many materials having excellent characteristics for a hole transport material are known.
  • charge transport layer polycarbonate resin and polyarylate resin have been mainly used as a binder resin.
  • low residual potential and high responsiveness in a multilayer type photoreceptor have been realized using polyarylate resin and a charge transport substance having specific properties for a photosensitive layer by designing the surface of the electrophotographic photoreceptor such that the surface has a specific universal hardness and elastic deformation ratio (PTL 1).
  • PTL 1 specific universal hardness and elastic deformation ratio
  • Such multilayer type photoreceptor is often used for the negative charging system. In a case where the photoreceptor is charged by negative corona discharge, there are cases where the generated ozone adversely affects the environment and photoreceptor properties.
  • the single-layer type photoreceptor is a photoreceptor that may use any of the negative charging system and the positive charging system, and in a case where the positive charging system is employed for the single-layer type photoreceptor, ozone generation which is the problem in the use of the multilayer type photoreceptor can be reduced. Therefore, despite some of the inferior characteristics compared to those of the negative charging multilayer type photoreceptor in terms of electrical properties, the single-layer type photoreceptor has been partly put into practical use as a single-layer type electrophotographic photoreceptor for positive charging (PTL 2), and studies regarding miniaturization and sensitivity enhancement thereof are ongoing.
  • PTL 2 positive charging
  • a technique which is capable of providing a single-layer type electrophotographic photoreceptor which does not cause a memory image generation even in an image forming apparatus in which an erase step is not performed and includes a photosensitive layer that contains, in the binder resin, a phthalocyanine compound as a charge generating agent, a hole transport agent, and an electron transport agent, the content of the phthalocyanine compound being 0.1 to 4 wt % with respect to the binder resin mass, the thickness of the photosensitive layer being 10 to 35 ⁇ m, and the absolute difference between positive and negative polarity sensitivities measured under certain conditions being 500 V or less (PTL 3).
  • a technique which is capable of providing a photosensitive layer of which the half decay exposure at the time of positive charging is 0.18 ⁇ J/cm 2 or less, and the half decay exposure at the time of negative charging is 2 times to 12 times the half decay exposure at the time of positive charging (PTL 4).
  • an object of the present invention is to provide a single-layer type electrophotographic photoreceptor for positive charging having satisfactory initial memory while retaining satisfactory electrical properties and an image forming apparatus including the photoreceptor and exhibiting satisfactory image density.
  • a photoreceptor As a result of intensive studies, the present inventors have found that by allowing a photoreceptor to have a photosensitive layer containing a charge transport substance, a binder resin, and a compound having a specific structure, a photoreceptor that is stable with less decrease in initial charging properties and has favorable initial memory under ozone exposure while retaining the electrical properties during an electrophotographic process in which a charge erase step is not performed, can be provided and has completed the present invention as described below.
  • the gist of the present invention resides in the following ⁇ 1> to ⁇ 9>.
  • a single-layer type electrophotographic photoreceptor for positive charging comprising: a conductive support; and a photosensitive layer disposed on the conductive support, the photosensitive layer including a binder resin, a charge generation material, a hole transport material, and an electron transport material within the same layer,
  • the electron transport material is a compound represented by Formula (1)
  • the photosensitive layer contains an aromatic compound represented by Formula (7) and having a molecular weight of 180 to 400:
  • R 1 to R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms that may have a substituent, or an alkenyl group having 1 to 20 carbon atoms that may have a substituent, R 1 and R 2 , or R 3 and R 4 may be bonded to each other to form a cyclic structure, and X represents an organic residue having a molecular weight of 120 to 250]
  • Ar 1 and Ar 2 each independently represent an aryl group that may have a substituent, and x and y each independently represent an integer of 0 to 2].
  • ⁇ 2> The single-layer type electrophotographic photoreceptor for positive charging according to the ⁇ 1>, wherein the content of the aromatic compound represented by Formula (7) in the photosensitive layer is 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the binder resin.
  • ⁇ 3> The single-layer type electrophotographic photoreceptor for positive charging according to the ⁇ 1> or ⁇ 2>, wherein the charge generation material is a phthalocyanine pigment.
  • ⁇ 4> The single-layer type electrophotographic photoreceptor for positive charging according to any one of the ⁇ 1> or ⁇ 3>, wherein the binder resin is a polycarbonate resin.
  • ⁇ 5> The single-layer type electrophotographic photoreceptor for positive charging according to any one of the ⁇ 1> to ⁇ 4>, wherein in Formula (1), X is an organic residue represented by any one of Formulae (3) to (6):
  • R 5 to R 7 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms
  • R 8 to R 11 each independently represent a hydrogen atom, halogen atom, or an alkyl group having 1 to 6 carbon atoms
  • R 12 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom
  • R 13 and R 14 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms].
  • An electrophotographic photoreceptor cartridge comprising: the single-layer type electrophotographic photoreceptor for positive charging according to any one of the ⁇ 1> to ⁇ 5>; and at least one selected from the group consisting of a charging device for charging the electrophotographic photoreceptor, an exposure device for exposing the charged electrophotographic photoreceptor so as to form an electrostatic latent image thereon, and a developing device for developing the electrostatic latent image formed on the electrophotographic photoreceptor.
  • An image forming apparatus comprising: the single-layer type electrophotographic photoreceptor for positive charging according to any one of the ⁇ 1> to ⁇ 5>; a charging device for charging the electrophotographic photoreceptor; an exposure device for exposing the charged electrophotographic photoreceptor to light so as to form an electrostatic latent image thereon; and a developing device for developing the electrostatic latent image formed on the electrophotographic photoreceptor.
  • the image forming apparatus according to the ⁇ 7> which does not provide light for charge erase.
  • the single-layer type electrophotographic photoreceptor for positive charging according to any one of the ⁇ 1> to ⁇ 5> which is used in an electrophotographic process which does not provide light for charge erase.
  • the present invention makes it possible to provide an electrophotographic photoreceptor that, even when exposed to ozone, is stable without a decrease of initial charging properties and has excellent initial memory, while retaining the electrical properties during an electrophotographic process in which a charge erase step is not performed, an electrophotographic photoreceptor cartridge, and a full-color image forming apparatus.
  • FIG. 1 is a schematic view showing the configuration of main components of one embodiment of an image forming apparatus of the invention.
  • FIG. 2 is an X-ray diffraction spectrum of an oxytitanium phthalocyanine used in Examples obtained with CuK ⁇ characteristic X-ray.
  • a single-layer type electrophotographic photoreceptor for positive charging according to the present invention includes a conductive support and a single-layer type photosensitive layer that is formed on the conductive support and contains a binder resin, a charge generation material, a hole transport material, and an electron transport material within the same layer.
  • the electron transport material is a compound represented by Formula (1), and an aromatic compound represented by Formula (2) and having a molecular weight of 180 to 400 is contained in the photosensitive layer.
  • the content of the aromatic compound represented by Formula (2) and having a molecular weight of 180 to 400 with respect to 100 parts by mass of the binder resin is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and still more preferably 10 parts by mass or more from the standpoint of characteristics stabilization of the photoreceptor upon repeated use, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less, even more preferably 30 parts by mass or less, and still more preferably 25 parts by mass or less from the standpoint of characteristics stabilization of the photoreceptor upon repeated use.
  • the thickness of the single-layer type photosensitive layer is preferably 45 ⁇ m or less from the standpoint of film formation properties of the photosensitive layer, and more preferably 40 ⁇ m or less from the standpoint of high resolution.
  • the thickness of the single-layer type photosensitive layer is preferably 15 ⁇ m or more, from the standpoint of long life of the photoreceptor, and more preferably 20 ⁇ m or more, from the standpoint of image stability.
  • the photosensitive layer includes a compound represented by Formula (1) as an electron transport material.
  • R 1 to R 4 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms that may have a substituent, or an alkenyl group having 1 to 20 carbon atoms that may have a substituent.
  • R 1 and R 2 , or R 3 and R 4 may be bonded to each other to form a cyclic structure.
  • X represents an organic residue having a molecular weight of 120 to 250.
  • R 1 to R 4 each independently represent a hydrogen atom, or an alkyl group having 1 to 20 carbon atoms, or an alkenyl group having 1 to 20 carbon atoms that may have a substituent.
  • alkyl group having 1 to 20 carbon atoms that may have a substituent include linear alkyl groups such as a methyl group, an ethyl group, and a hexyl group, branched alkyl groups such as an iso-propyl group, a tert-butyl group, and a tert-amyl group, and cyclic alkyl groups such as a cyclohexyl group and a cyclopentyl group.
  • the alkyl group is preferably a linear alkyl group or a branched alkyl group, among which a methyl group, a tert-butyl group, and a tert-amyl group are more preferable, and from the standpoint of solubility in organic solvents used in coating fluids, a tert-butyl group and a tert-amyl group are even more preferable.
  • R 1 to R 4 may be bonded to form a cyclic structure.
  • R 1 and R 2 may preferably be bonded together to form an aromatic ring, and it is more preferable that both R 1 and R 2 are ethenyl groups and bonded together to form a benzene ring structure.
  • X represents an organic residue having a molecular weight of 120 to 250, and X is preferably an organic residue represented by any one of the following Formulae (3) to (6) from the standpoint of the photo-attenuation characteristics of the photoreceptor.
  • R 5 to R 7 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
  • R 8 to R 11 each independently represent a hydrogen atom, halogen atom, or an alkyl group having 1 to 6 carbon atoms.
  • R′ 2 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom.
  • R 13 and R 14 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms.
  • Examples of the alkyl group having 1 to 6 carbon atoms in R 5 to R 14 include linear alkyl groups such as a methyl group, an ethyl group, and a hexyl group, branched alkyl groups such as an iso-propyl group, a tert-butyl group, and a tert-amyl group, and cyclic alkyl groups such as a cyclohexyl group. From the standpoint of electron-transporting ability, a methyl group, a tert-butyl group, and a tert-amyl group are more preferable.
  • halogen atom examples include fluorine, chlorine, bromine, and iodine, and from the standpoint of electron-transporting ability, chlorine is preferable.
  • aryl group having 6 to 12 carbon atoms examples include a phenyl group and a naphthyl group, and from the standpoint of film property of the photosensitive layer, a phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable.
  • X is preferably an organic residue represented by Formula (3) or (4) from the standpoint of image stability upon repeated image formation, and X is more preferably an organic residue represented by Formula (3).
  • a compound represented by Formula (1) may be used alone, or may be used in combination with another compound represented by Formula (1) having a different structure, or even may be used in combination with another electron transport material.
  • the electron transport material is usually used in an amount of 5 parts by mass or more with respect to 100 parts by mass of the binder resin.
  • the amount thereof is preferably 10 parts by mass or more from the standpoint of reducing of residual potential, and the amount thereof is preferably 20 parts by mass or more from the standpoints of stability upon repeated use and charge mobility.
  • the charge transport material is usually used in an amount of 100 parts by mass or less.
  • the amount thereof is preferably 80 parts by mass or less, more preferably 60 parts by weight or less, and even more preferably 50 parts by weight or less.
  • the photosensitive layer includes an aromatic compound represented by Formula (2) having a molecular weight of 180 to 400.
  • a and B each independently represent any of an aryl group having 6 to 20 carbon atoms that may have a substituent, an aralkyl group having 7 to 20 carbon atoms that may have a substituent, an acyl group having 2 to 20 carbon atoms that may have a substituent, or an alkyl group having 6 to 20 carbon atoms that may have a substituent.
  • Either A or B includes a group exhibiting aromaticity.
  • examples of the aryl group having 6 to 20 carbon atoms that may have a substituent include a phenyl group, a naphthyl group, a biphenyl group, an anthryl group and a phenanthryl group.
  • a phenyl group, a naphthyl group, and a biphenyl group are preferred, and from the standpoint of solubility in organic solvents used for a coating solvent, a phenyl group and a naphthyl group are more preferred, and a naphthyl group is particularly preferred.
  • Examples of the aralkyl group having 7 to 20 carbon atoms that may have a substituent include a benzyl group, a phenethyl group, and a naphthyl methyl group. Among them, from the standpoint of versatility of the starting materials, a benzyl group and a naphthyl methyl group are preferred, and a benzyl group is more preferred.
  • alkyloxy groups such as an acetyl group, and a cyclohexylcarbonyl group
  • arylcarbonyl groups such as a benzoyl group, a naphthylcarbonyl group, and a biphenylcarbonyl group.
  • alkyloxy groups such as an acetyl group, and a cyclohexylcarbonyl group
  • arylcarbonyl groups such as a benzoyl group, a naphthylcarbonyl group, and a biphenylcarbonyl group.
  • alkyl groups having 6 to 20 carbon atoms that may have a substituent include cyclic alkyl groups such as a cyclohexyl group, linear alkyl groups such as an octyl group, and branched alkyl groups such as a 2,4-dimethylhexyl group.
  • cyclic alkyl groups such as a cyclohexyl group
  • linear alkyl groups such as an octyl group
  • branched alkyl groups such as a 2,4-dimethylhexyl group.
  • alkyl groups having a cyclic structure are preferred, and more preferred of those alkyl groups is a cyclohexyl group.
  • Examples of the substituents that A and B may have include an alkyl group, an aryl group, an alkoxy group, an acyl group, acyloxy group, and a halogen atom.
  • alkyl groups include linear alkyl groups such as a methyl group, an ethyl group, an n-propyl group and an n-butyl group, and branched alkyl groups such as an isopropyl group and an ethylhexyl group; and cyclic alkyl groups such as a cyclohexyl group.
  • aryl groups include a phenyl group, naphthyl group, biphenyl group, anthryl group, and a phenanthryl group.
  • alkoxy group examples include linear alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group and an n-butoxy group, branched alkoxy groups such as an isopropoxy group and an ethylhexyloxy group, cyclic alkoxy groups such as a cyclohexyloxy group, and alkoxy groups having fluorine atoms such as a trifluoromethoxy group, a pentafluoroethoxy group, and a 1,1,1-trifluoroethoxy group.
  • the acyl group include an acetyl group, a benzoyl group, and a naphthylcarbonyl group.
  • the acyloxy group examples include a benzoyloxy group and a naphthylcarboxyoxy group.
  • the halogen atom include a fluorine atom, chlorine atom, and a bromine atom.
  • an alkyl group having 1 to 6 carbon atoms preferred are an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 1 to 8 carbon atoms, and an acyloxy group having 1 to 8 carbon atoms, and from the standpoint of handleability during production, more preferred of those are an alkyl group having 1 to 6 carbon atoms and an acyloxy group having 1 to 8 carbon atoms.
  • the molecular weight of the aromatic compound is, from the standpoint of film-forming properties of the photosensitive layer, preferably 370 or less, more preferably 350 or less, and even more preferably 325 or less, and particularly preferably 300 or less, and from the standpoint of compatibility between the photosensitive layer and the aromatic compound, is preferably 190 or more, and more preferably 200 or more.
  • a compound represented by Formula (7) is preferable from the standpoint of initial memory.
  • Ar 1 and Ar 2 each independently represent a phenyl group or a naphthyl group that may have any of an alkyl group, an alkoxy group, and a phenyl group.
  • x and y represent 0 or 1.
  • the alkyl group, the alkoxy group, and the phenyl group that may be included in Ar 1 and Ar 2 are the same as those described as the substituents that may be included in A and B.
  • An aromatic compound represented by Formula (2) may be used alone, or may be used in combination with another aromatic compound represented by Formula (2) having a different structure. Structures of the aromatic compounds are exemplified below. The following structures are exemplified in order to make the present invention more concrete and the invention is not limited to the following structures insofar as they do not depart from the concept of the present invention.
  • the aromatic compound is usually used in an amount of 1 part by mass or more with respect to 100 parts by mass of the binder resin.
  • the amount of the aromatic compound is preferably 3 parts by mass or more from the standpoint of initial memory, and more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more from the standpoint of stability of electric potential upon repeated use.
  • the aromatic compound is usually used in an amount of 50 parts by mass or less.
  • the amount thereof is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less.
  • the aromatic compound is usually used in an amount of 1 part by mass or more with respect to 100 parts by mass of the electron transport material. From the standpoint of initial memory, the amount thereof is preferably 10 parts by mass or more. From the standpoint of repeating memory, the amount thereof is preferably 30 parts by mass or more. From the standpoint of stability of the coating fluids, the aromatic compound is usually used in an amount of 150 parts by mass or less. From the standpoint of electrical properties, the amount thereof is preferably 100 parts by mass or less, and more preferably 80 parts by mass or less.
  • binder resin examples include thermoplastic resins and various thermosetting resins, such as vinyl polymers, e.g., polymethyl methacrylate, polystyrene, and polyvinyl chloride, copolymers thereof, and polycarbonate, polyarylate, polyester, polyester polycarbonate, polysulfone, phenoxy, epoxy, and silicone resins.
  • PVPE vinyl polymers
  • polystyrene polymethyl methacrylate
  • polystyrene polyvinyl chloride
  • copolymers thereof examples include polycarbonate, polyarylate, polyester, polyester polycarbonate, polysulfone, phenoxy, epoxy, and silicone resins.
  • Preferred of these resins are polycarbonate resins and polyarylate resins from the standpoint of photo-attenuation characteristics and mechanical strength of the photoreceptor.
  • repeating structural units suitable for the binder resins are shown below.
  • the following examples are mere examples, and known binder resins may be used so long as the use thereof does not depart from the spirit of the invention.
  • the viscosity-average molecular weight of the binder resin is, from the standpoint of mechanical strength, usually 20,000 or more, preferably 30,000 or more, more preferably 40,000 or more, and even more preferably 50,000 or more, and from the standpoint of production of coating fluid used for photosensitive layer formation, the viscosity-average molecular weight thereof is usually 150,000 or less, preferably 120,000 or less, and more preferably 100,000 or less.
  • the charge generation material examples include inorganic photoconductive materials, such as selenium, alloys thereof, and cadmium sulfide, and organic photoconductive materials such as organic pigments. Preferred of these are organic photoconductive materials, and particularly preferred are organic pigments.
  • organic pigments examples include phthalocyanine pigments, azo pigments, dithioketopyrrolopyrrole pigments, squalene (squarylium) pigments, quinacridone pigments, indigo pigments, perylene pigments, polycyclic quinone pigments, anthanthrone pigments, and benzimidazole pigments.
  • organic pigments are phthalocyanine pigments and azo pigments.
  • the organic pigment is used usually in the form of a dispersion layer in which fine particles thereof have been bound with any of various binder resins.
  • the phthalocyanine pigment as the charge generation material, use may be made specifically of metal-free phthalocyanines and phthalocyanine compounds to which a metal, e.g., copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, or aluminum, or an oxide, halide, hydroxide, alkoxide, or another form of the metal has coordinated, these phthalocyanines and phthalocyanine compounds having respective crystal forms, and phthalocyanine dimers in which oxygen or other atoms are used as crosslinking atoms.
  • a metal e.g., copper, indium, gallium, tin, titanium, zinc, vanadium, silicon, germanium, or aluminum, or an oxide, halide, hydroxide, alkoxide, or another form of the metal has coordinated, these phthalocyanines and phthalocyanine compounds having respective crystal forms, and phthalocyanine dimers in which oxygen or other atoms are used as crosslinking atoms.
  • X-form and ⁇ -form metal-free phthalocyanines which are crystal forms having high sensitivity
  • A-form also called ⁇ -form
  • B-form also called ⁇ -form
  • D-form also called Y-form
  • titanyl phthalocyanines other name: oxytitanium phthalocyanines
  • vanadyl phthalocyanines chloroindium phthalocyanines, hydroxyindium phthalocyanines, II-form and other chlorogallium phthalocyanines
  • V-form and other hydroxygallium phthalocyanines G-form, I-form, and other ⁇ -oxo-gallium phthalocyanine dimers
  • II-form and other ⁇ -oxo-aluminum phthalocyanine dimers are particularly preferred.
  • phthalocyanines are A-form (also called ⁇ -form) and B-form (also called ⁇ -form) titanyl phthalocyanines, D-form (Y-form) titanyl phthalocyanine characterized by showing a distinct peak at a diffraction angle 2 ⁇ ( ⁇ 0.2°) of 27.1° or 27.3° in X-ray powder diffractometry, II-form chlorogallium phthalocyanine, V-form hydroxygallium phthalocyanine, the hydroxygallium phthalocyanine characterized by having a most intense peak at 28.1° or characterized by having no peak at 26.2°, having a distinct peak at 28.1°, and having a half-value width W at 25.9° of 0.1° ⁇ W ⁇ 0.4°, a G-form ⁇ -oxo-gallium phthalocyanine dimer, and X-form metal-free phthalocyanines.
  • A-form also called ⁇ -form
  • B-form also called ⁇ -form titany
  • a single phthalocyanine compound may be used alone, or a mixture of several phthalocyanine compounds or a phthalocyanine compound in a mixed-crystal state may be used.
  • the state in which phthalocyanine compounds are mixed or the mixed-crystal state may be one obtained by mixing the constituent elements later, or may be one formed in steps for phthalocyanine compound production and treatments, such as synthesis, pigment formation, crystallization, etc.
  • Known as such treatments are an acid pasting treatment, grinding treatment, solvent treatment, and the like.
  • Examples of methods for producing a mixed-crystal state include a method in which two kinds of crystals are mixed together and the resultant mixture is mechanically ground and made amorphous and is then subjected to a solvent treatment to thereby convert the amorphous state into a specific crystalline state, as described in JP-A-10-48859.
  • the particle diameter of the charge generation material is usually 1 ⁇ m or less, and preferably used are particles having a particle diameter of 0.5 ⁇ m or less.
  • the amount of the charge generation material to be dispersed in the photosensitive layer is usually 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1.0 part by mass or more with respect to 100 parts by mass of the binder resin, and from the standpoint of sensitivity, is usually 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less.
  • the hole transport material examples include electron-donating substances such as heterocyclic compounds, e.g., carbazole derivatives, indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, and benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, aryl amine derivatives, stilbene derivatives, butadiene derivatives, and enamine derivatives, and compounds each made up of two or more of these compounds bonded together or polymers each including, in the main chain or a side chain thereof, a group constituted of any of these compounds.
  • electron-donating substances such as heterocyclic compounds, e.g., carbazole derivatives, indole derivatives, imidazole derivatives, oxazole derivatives, pyrazole derivatives, thiadiazole derivatives, and benzofuran derivatives, aniline derivatives, hydrazone derivatives, aromatic amine derivatives, aryl
  • those electron-donating substances are carbazole derivatives, aromatic amine derivatives, aryl amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and compounds each made up of two or more of these compounds bonded together or polymers each including, in the main chain or a side chain thereof, a group constituted of any of these compounds.
  • Particularly preferred among them are carbazole derivatives, aromatic amine derivatives, aryl amine derivatives, stilbene derivatives, butadiene derivatives, enamine derivatives, and compounds each made up of two or more of these compounds bonded together.
  • hole transport materials preferred are compounds having a structure of HTM 34, 35, 36, 37, 39, 40, 41, 42, 43, or 44 from the standpoint of residual potential.
  • the ratio of the hole transport material to be blended is usually 20 parts by mass or more with respect to 100 parts by mass of the binder resin. Within the range, the ratio of the hole transport material to be blended is preferably 30 parts by mass or more with respect to 100 parts by mass of the binder resin from the standpoint of reducing residual potential, and more preferably 40 parts by mass or more from the standpoints of stability upon repeated use and charge mobility.
  • the ratio of the hole transport material to be blended is preferably 200 parts by mass or less with respect to 100 parts by mass of the binder resin from the standpoint of thermal stability of the photosensitive layer, and more preferably 150 parts by mass or less from the standpoints of compatibility between the hole transport material and the binder resin.
  • the ratio of the charge transport material to be blended is usually 20 parts by mass or more with respect to 100 parts by mass of the binder resin. Within the range, the ratio of the charge transport material to be blended is preferably 30 parts by mass or more with respect to 100 parts by mass of the binder resin from the standpoint of reducing residual potential, and more preferably 40 parts by mass or more from the standpoints of stability upon repeated use and charge mobility.
  • the ratio of the charge transport material to be blended is preferably 200 parts by mass or less with respect to 100 parts by mass of the binder resin from the standpoint of thermal stability of the photosensitive layer, and more preferably 150 parts by mass or less, even more preferably 125 parts by mass or less, and still more preferably 100 parts by mass or less from the standpoint of compatibility between the charge transport material and the binder resin. In a case where two or more the charge transport materials are used, the total amount of the electron transport material is adjusted to fall within the above range.
  • the conductive support is not particularly limited, mainly used as the conductive support is, for example, a metallic material such as aluminum, an aluminum alloy, stainless steel, copper, or nickel, a resinous material to which electrical conductivity has been imparted by adding a conductive powder, e.g., a metal, carbon, or tin oxide powder, or a resin, glass, paper, or the like, having a surface on which a conductive material, e.g., aluminum, nickel, or ITO (indium oxide/tin oxide) has been vapor deposited or applied.
  • a conductive powder e.g., a metal, carbon, or tin oxide powder
  • a resin, glass, paper, or the like having a surface on which a conductive material, e.g., aluminum, nickel, or ITO (indium oxide/tin oxide) has been vapor deposited or applied.
  • a conductive powder e.g., aluminum, nickel, or ITO (indium oxide/tin oxide) has been vapor
  • Examples of the form of the conductive support include a drum, sheet, belt, or the like. Use may be made of a metallic conductive support having a surface coated with a conductive material having a suitable resistance in order to control the conductivity and surface properties thereof, and to coat defects.
  • this material may be used after an anodized coating film is formed thereon.
  • the material is preferably subjected to a pore-filling treatment by a known method.
  • the surface of the support may be smooth, or may have been roughened by using a special machining method or by performing a grinding treatment.
  • a support having a roughened surface obtained by incorporating particles with an appropriate particle diameter into the material for constituting the support.
  • a drawn pipe can be used as such without subjecting the pipe to machining, for the purpose of cost reduction.
  • An undercoat layer may be disposed between the conductive support and the photosensitive layer in order to improve adhesiveness, blocking properties, etc.
  • the undercoat layer use may be made, for example, of a resin alone or a resin in which particles of a metal oxide or the like or an organic pigment or the like is dispersed.
  • Examples of the metal oxide particles used for the undercoat layer include particles of a metal oxide containing one metallic element, such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, and iron oxide, and particles of a metal oxide containing a plurality of metallic elements, such as calcium titanate, strontium titanate, and barium titanate.
  • a metal oxide containing one metallic element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, and iron oxide
  • particles of a metal oxide containing a plurality of metallic elements such as calcium titanate, strontium titanate, and barium titanate.
  • a metal oxide containing one metallic element such as titanium oxide, aluminum oxide, silicon oxide, zirconium oxide, zinc oxide, and iron oxide
  • a metal oxide containing a plurality of metallic elements such as calcium titanate, strontium titanate, and barium titanate.
  • Preferred of these metal oxide particles are titanium oxide and aluminum oxide. Particularly preferred is titanium oxide.
  • the titanium oxide particles may have a surface which has been treated with an inorganic material such as tin oxide, aluminum oxide, antimony oxide, zirconium oxide, and silicon oxide, or with an organic material such as stearic acid, a polyol and a silicone.
  • the crystal form of the titanium oxide particles to be utilized may be any of rutile, anatase, brookite, and amorphous.
  • the titanium oxide particles to be utilized may include particles in a plurality of crystal states.
  • metal oxide particles having various particle diameters can be utilized, from the standpoint of characteristics thereof and fluid stability, preferably used of those particles are particulate metal oxides having an average primary-particle diameter of 1 nm to 100 nm, and particularly preferably 10 nm to 50 nm.
  • the undercoat layer is preferably formed so as to be configured of a binder resin and metal oxide particles dispersed therein.
  • the binder resin to be used in the undercoat layer include phenoxy, epoxy, polyvinyl pyrrolidone, polyvinyl alcohol, casein, polyacrylic acid, celluloses, gelatin, starch, polyurethane, polyimide and polyamide, and one of these resins may be used alone, or may be used together with a hardener to come into a hardened state.
  • alcohol-soluble copolyamides, modified polyamide, and the like are preferred because of the excellent dispersibility and applicability they exhibit.
  • a layer corresponding to the charge generation layer that constitutes a multilayer type photoreceptor can be employed as the undercoat layer of the single-layer type photosensitive layer.
  • an undercoat layer that has been coated with phthalocyanine pigments, azo pigments, perylene pigments, or the like dispersed in the binder resin.
  • the undercoat layer exhibits excellent adhesiveness and electrical properties.
  • the binder resin are polyvinyl acetal resins, and polyvinyl butyral resins are particularly preferred from the standpoint of electrical properties.
  • the addition ratio of dispersants such as particles or pigments to the binder resin can be selected at will, the ratio is preferably in a range of 10 mass % to 500 mass % from the standpoints of dispersion stability and applicability.
  • thickness of the undercoat layer can be selected at will, the thickness is preferably 0.1 ⁇ m to 25 ⁇ m from the standpoint of the photoreceptor properties and applicability.
  • a known antioxidant and the like may be incorporated into the undercoat layer.
  • Several layers having different constitutions may also be provided as the undercoat layer.
  • the photosensitive layer or respective layers that constitute the photosensitive layer may contain known additives such as an antioxidant, plasticizer, ultraviolet absorber, electron-attracting compound, leveling agent, and visible-light-shielding agent for the purposes of enhancing the film-forming properties, flexibility, applicability, non-fouling properties, gas resistance, light resistance, and the like.
  • particles formed of a fluororesin, silicone resin, polyethylene resin, or the like, or particles of an inorganic compound may be incorporated into the charge transport layer for the purposes of reducing the frictional resistance or wear of the photoreceptor surface, heightening the efficiency of toner transfer from the photoreceptor to a transfer belt or to paper, and the like.
  • the layers that constitutes the above-described photoreceptor may be formed by repeatedly and successively performing application and drying steps, in which a coating fluid obtained by dissolving or dispersing, in a solvent, substances to be incorporated is applied to a conductive support by a known method, such as dip coating, spray coating, nozzle coating, bar coating, roll coating, or blade coating, and dried to form each layer.
  • solvents or dispersion medium to be used in preparation of the coating fluid is not limited to particular solvents or dispersion media, specific examples thereof include alcohols such as methanol, ethanol, propanol, and 2-methoxyethanol, ethers such as tetrahydrofuran, 1,4-dioxane, and dimethoxyethane, esters such as methyl formate, ethyl acetate, ketones such as acetone, methyl ethyl ketone, cyclohexanone, and 4-methoxy-4-methyl-2-pentanone, aromatic hydrocarbons such as benzene, toluene, and xylene, chlorinated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, tetrachloroethane, 1,2-dichloropropane, and trichloroethylene, nitrogen-
  • the amount of the solvent or dispersion medium to be used is not particularly specified, the amount thereof is preferably adjusted, as appropriate, in accordance with the intended purpose of each layer and nature of the selected solvent and dispersion media so as to set properties such as the solid content concentration or viscosity of the coating fluid, to be in desired ranges.
  • the coating fluid is dried with heating in a temperature range of, usually, 30° C. to 200° C. for 1 minute to 2 hours either in a stationary atmosphere or with air blowing.
  • the heating temperature may be constant, or the heating for drying may be performed while changing the heating temperature.
  • FIG. 1 illustrates the configuration of main components of the apparatus.
  • embodiments of the present invention are not limited to the following description, and the embodiments can be freely modified without departing from the spirit and scope of the present invention.
  • the image forming apparatus includes an electrophotographic photoreceptor 1 , a charging device 2 , an exposure device 3 , and a developing device 4 , and may further include, as necessary, a transfer device 5 , a cleaning device 6 , and a fixing device 7 .
  • the electrophotographic photoreceptor 1 is not particularly limited as long as it is an electrophotographic photoreceptor according to the present invention.
  • FIG. 1 depicts, as an example thereof, a drum-shaped photoreceptor in which the above-described photosensitive layer is formed on a surface of a cylindrical conductive support.
  • the charging device 2 , the exposure device 3 , the developing device 4 , the transfer device 5 and the cleaning device 6 are respectively disposed along an outer peripheral surface of the electrophotographic photoreceptor 1 .
  • the charging device 2 which is the one that charges the electrophotographic photoreceptor 1 , uniformly charges a surface of the electrophotographic photoreceptor 1 to a predetermined potential.
  • typical charging devices include non-contact corona charging devices such as a corotron and a scorotron, and contact charging devices (direct charging devices) that charges the photoreceptor by bringing a charging member to which a voltage is being applied into contact with the photoreceptor surface.
  • Examples of the contact charging devices used in the invention include charging rollers and charging brushes.
  • the charging device depicted in FIG. 1 is a roller type-charging device (charging roller).
  • Charging rollers are typically produced by integrally molding a resin and additives such as a plasticizer with a metallic shaft and may have a multilayer structure as necessary.
  • a direct-current voltage only can be used or an alternating current superimposed on a direct current is also usable.
  • the exposure device 3 is not particularly limited as long as it is an exposure device that is capable of exposing the electrophotographic photoreceptor 1 to light and forming an electrostatic latent image on the photosensitive surface of the electrophotographic photoreceptor 1 .
  • Specific examples thereof include a halogen lamp, fluorescent lamp, laser (semiconductor laser or He—Ne laser), and LED. Exposure may be performed by an internal photoreceptor exposure technique, or the like.
  • the wavelength of the exposing light can be selected at will, use can be made of, for example, monochromatic light of 780 nm, monochromatic light having a slightly short wavelength in a range of 600 nm to 700 nm, monochromatic light having a short wavelength in a range of 380 nm 500 nm.
  • a toner T can be selected at will, use can be made of polymerization toners obtained by methods such as suspension polymerization, emulsion polymerization, and the like in addition to powdery toners.
  • polymerization toners preferred are toners having a small particle diameter of around 4 to 8 ⁇ m, and use can be made of the toner particles having various shapes from a nearly spherical shape to potato-like shape apart from sphere.
  • Polymerization toners which are excellent in terms of evenness in charging and transferability, are preferably used for increasing image quality.
  • the transfer device 5 is not limited to a particular kind, and use can be made of devices using any technique such as an electrostatic transfer technique, pressure transfer technique, adhesive transfer technique, or the like, e.g., corona transfer, roller transfer, or belt transfer.
  • the transfer device 5 includes a transfer charger, a transfer roller, and a transfer belt configured to face the electrophtographic photoreceptor 1 .
  • This transfer device 5 applies a predetermined voltage (transfer voltage) in a polarity opposite to the charge potential of the toner T, and thereby transfers a toner image formed on the electrophotographic photoreceptor 1 onto a recording paper (paper and medium) P.
  • the cleaning device 6 is not particularly limited, use may be made of any cleaning device such as a brush cleaner, magnetic brush cleaner, electrostatic brush cleaner, magnetic roller cleaner, blade cleaner, or the like.
  • the cleaning device 6 scrapes off residual toners attached to the photoreceptor 1 with a cleaning member to collect the residual toners.
  • the cleaning device 6 may be omitted.
  • the fixing device 7 includes an upper fixing member (fixing roller) 71 and a lower fixing member (fixing roller) 72 , and either the upper fixing member 71 or the lower fixing member 72 includes a heating member 73 in the inside thereof.
  • FIG. 1 depicts an example in which the heating device 73 is included in the upper fixing member 71 .
  • the respective fixing members 71 and 72 on the upper and lower portions use may be made of known thermal fixing members such as a fixing roll formed by coating a pipe of metal, e.g., stainless steel and aluminum with a silicon rubber, a fixing roll coated with Teflon (registered trademark) resin, and a fixing sheet.
  • either the upper fixing member 71 or the lower fixing member 72 may be configured so as to supply a release agent such as silicone oil for improving releasability thereof. They may also be configured so as to forcibly apply pressure to one another by a spring.
  • the toner that has been transferred onto the recording paper P is thermally heated until the toner is molten, while passing through between the upper fixing member 71 that has been heated to a predetermined temperature and the lower fixing member 72 . After passing therethrough, the toner is cooled and thereby fixed onto the recording paper P.
  • the fixing device may include a fixing device using any technique, e.g., hot-roller fixing, flash fixing, oven fixing, and pressure fixing, in addition to the ones used herein.
  • the electrophotographic apparatus configured as such records an image as follows. That is, first, the charging device 2 charges a surface (photosensitive surface) of the electrophotographic photoreceptor 1 to a predetermined potential (for example, ⁇ 600 V). At this time, the charging device 2 may charge the photosensitive surface of the electrophotographic photoreceptor using a direct-current voltage or may charge the same using an alternate-current voltage superimposed with a direct-current voltage.
  • a predetermined potential for example, ⁇ 600 V.
  • the charged photosensitive surface of the electrophotographic photoreceptor 1 is exposed to light by the exposure device 3 in accordance with an image to be recorded to form an electrostatic latent image on the photosensitive surface.
  • the developing device 4 develops the electrostatic latent image formed on the photosensitive surface of the electrophotographic photoreceptor 1 .
  • the developing device 4 forms the toner T supplied by a supply roller 43 into a thin layer using a regulating member (developing blade) 45 and charges the toner T to a predetermined polarity (here, the same polarity as that of the charge potential of the electrophotographic photoreceptor 1 : negative polarity) by means of frictional electrification, transfers the toner while supporting the toner with a developing roller 44 , and brings the toner into contact with the surface of the electrophotographic photoreceptor 1 .
  • a predetermined polarity here, the same polarity as that of the charge potential of the electrophotographic photoreceptor 1 : negative polarity
  • the charged toner T supported with the developing roller 44 comes into contact with the surface of the electrophotographic photoreceptor 1 , a toner image corresponding to the electrostatic latent image is formed on the photosensitive surface of the electrophotographic photoreceptor 1 .
  • the toner image is transferred by the transfer device 5 onto the recording paper P. Thereafter, the toners remaining on the photosensitive surface of the electrophotographic photoreceptor 1 without being transferred is removed by the cleaning device 6 .
  • the recording paper P After the transfer of the toner image onto the recording paper P, the recording paper P is made to pass through the fixing device 7 such that the toner image is thermally fixed onto the recording paper P, whereby obtaining a final image.
  • the image forming apparatus may be configured, for example, to be capable of carrying out a charge erase step.
  • the charge erase step is a step of carrying out eliminating the charges by exposing the electrophotographic photoreceptor to light, and as a charge removal device, a fluorescent lamp or LED may, for example, be used. Further, regarding the intensity of the light used in the charge erase step, light having exposure energy at least three times the exposure light is frequently used. From the standpoints of miniaturization and energy conservation, the charge erase step is preferably omitted.
  • the image forming apparatus may further be modified such that the image forming apparatus is configured, for example, to be capable of carrying out a pre-exposure step or an auxiliary charging step, or to be capable of offset printing, or further may be configured as a full-color tandem system employing multiple kinds of toners.
  • one or two or more of the charging device 2 , the exposure device 3 , the developing device 4 , the transfer device 5 , the cleaning device 6 , and the fixing device 7 may be combined with the electrophotographic photoreceptor 1 to configure an integrated cartridge (hereinafter, referred as “electrophotographic photoreceptor cartridge” as appropriate) so that this electrophotographic photoreceptor cartridge can be mounted on and demounted from the main body of an electrophotographic apparatus such as a copier or a laser-beam printer.
  • an integrated cartridge hereinafter, referred as “electrophotographic photoreceptor cartridge” as appropriate
  • the resin to be measured is dissolved in dichloromethane to prepare a solution having a concentration C of 6.00 g/L.
  • a Ubbelohde capillary viscometer having a solvent (dichloromethane) flow time t0 of 136.16 seconds
  • the sample solution is examined for flow time tin a thermostatic water bath set at 20.0° C.
  • the viscosity-average molecular weight Mv is calculated according to the following equations.
  • 160 parts by mass of the pigment dispersion thus obtained was mixed with 100 parts by mass of a 5 mass % 1,2-dimethoxyethane solution of polyvinyl butyral (trade name, #6000C; manufactured by Denki Kagaku Kogyo K.K.) and an appropriate amount of 4-methoxy-4-methyl-2-pentanone so as to prepare a coating fluid for undercoating with a solid content concentration of 4.0 mass %.
  • HTM-1 hole transport material represented by Structural Formula
  • ETM-1 electron transport material represented by Structural Formula
  • AD-1 20 parts by mass of a compound represented by Structural Formula (AD
  • the above-described dispersion was further added, and the mixture thus obtained was uniformly mixed with a homogenizer so as to obtain a coating fluid for single-layer type photosensitive layer.
  • the coating fluid for single-layer type photosensitive layer prepared as such was applied onto the undercoat layer to form a film having a thickness of 25 ⁇ m after drying, whereby obtaining Photoreceptor A which is a single-layer type electrophotographic photoreceptor for positive charging.
  • Photoreceptor B was produced in the same manner as in Example 1 except that the use amount of the compound represented by Formula (AD-1) was changed to 15 parts by mass.
  • Photoreceptor C was produced in the same manner as in Example 1 except that the use amount of the compound represented by Formula (AD-1) was changed to 10 parts by mass.
  • Photoreceptor D was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was replaced with a compound represented by Formula (AD-2).
  • Photoreceptor E was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was replaced with a compound represented by Formula (AD-3).
  • Photoreceptor F was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was replaced with a compound represented by Formula (AD-4).
  • Comparative photoreceptor A was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was not used.
  • Comparative photoreceptor B was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was replaced with 8 parts by mass of a compound represented by Formula (AD-5).
  • Comparative photoreceptor C was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was replaced with 2 parts by mass of a compound represented by Formula (AD-6).
  • Comparative photoreceptor D was produced in the same manner as in Example 1 except that the compound represented by Formula (AD-1) was replaced with 20 parts by mass of a compound represented by Formula (AD-7).
  • Comparative photoreceptor E was produced in the same manner as in Example 1 except that the compound represented by Formula (ETM-1) was replaced with a compound represented by Formula (ETM-2).
  • Each of the electrophotographic photoreceptors obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was mounted in a drum cartridge for A4 monochrome printer [HL 5240 (printing speed: monochrome 24 rpm, resolution: 1200 dpi, exposure source: laser, charging system: scorotron) manufactured by Brother Industries, Ltd.], and the drum cartridge was set in the above printer.
  • A4 monochrome printer [HL 5240 (printing speed: monochrome 24 rpm, resolution: 1200 dpi, exposure source: laser, charging system: scorotron) manufactured by Brother Industries, Ltd.]
  • the printer used in the test does not perform photo-static charge elimination process.
  • the upper portion text pattern is memorized as a memory on the photoreceptor, which affects image formation of the next rotation. That is, there are cases in which the text pattern appears in the half tone portion as a memory image.
  • the extent to which the memory image was visible was evaluated in 5 ranks based on visual observation results, with rank 1 being the least visible memory image and rank 5 being the most clearly observed memory image. The evaluation results are shown in Table-1.
  • a method of performing ozone resistance evaluation test is described below.
  • sheet-shaped photoreceptors obtained in accordance with the producing method of the sheet-shaped photoreceptor for ozone resistance evaluation were charged by applying a current of 25 ⁇ A to a corotron charger, and the charge values of the photoreceptors were defined as V1.
  • the photoreceptors were exposed to ozone having a concentration of 300 ppm for 2 hours, and the charge values after exposure were measured in the same manner, and the charge values of the photoreceptors were defined as V2.
  • A: Charge holding ratio 65% or higher

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Emergency Medicine (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Photoreceptors In Electrophotography (AREA)
US15/702,494 2015-03-13 2017-09-12 Single-layer type electrophotographic photoreceptor for positive charging, electrophotographic photoreceptor cartridge, and image forming apparatus Abandoned US20180004101A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2015050946 2015-03-13
JP2015-050946 2015-03-13
PCT/JP2016/057676 WO2016148035A1 (ja) 2015-03-13 2016-03-10 正帯電用単層型電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/057676 Continuation WO2016148035A1 (ja) 2015-03-13 2016-03-10 正帯電用単層型電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置

Publications (1)

Publication Number Publication Date
US20180004101A1 true US20180004101A1 (en) 2018-01-04

Family

ID=56918705

Family Applications (1)

Application Number Title Priority Date Filing Date
US15/702,494 Abandoned US20180004101A1 (en) 2015-03-13 2017-09-12 Single-layer type electrophotographic photoreceptor for positive charging, electrophotographic photoreceptor cartridge, and image forming apparatus

Country Status (4)

Country Link
US (1) US20180004101A1 (ja)
JP (1) JP6662111B2 (ja)
CN (1) CN107407895B (ja)
WO (1) WO2016148035A1 (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11287756B2 (en) 2017-03-01 2022-03-29 Mitsubishi Chemical Corporation Positive charging electrophotographic photoreceptor, electrophotographic cartridge and image forming apparatus

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018061368A1 (ja) * 2016-09-29 2018-04-05 京セラドキュメントソリューションズ株式会社 電子写真感光体、プロセスカートリッジ及び画像形成装置
JP7204419B2 (ja) * 2018-10-24 2023-01-16 キヤノン株式会社 電子写真感光体、プロセスカートリッジ及び電子写真装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6593047B2 (en) * 2000-08-31 2003-07-15 Kyocera Mita Corporation Single-layer type electrophotosensitive material
US20030211413A1 (en) * 2002-05-10 2003-11-13 Xerox Corporation. Imaging members
US20060183044A1 (en) * 2005-02-16 2006-08-17 Samsung Electronics Co., Ltd. Electrophotographic photoreceptor containing asymmetric naphthalenetetracarboxylic acid diimide derivatives and electrophotographic imaging apparatus employing the same
US7195851B2 (en) * 2001-03-30 2007-03-27 Yamanashi Electronics Co., Ltd. Charge-transfer material and process for producing the same, electron-transfer agent, photoreceptor for electrophotography and organic electroluminescence element using said charge-transfer material
JP2011170041A (ja) * 2010-02-17 2011-09-01 Mitsubishi Chemicals Corp 電子写真感光体、電子写真感光体カートリッジ及び画像形成装置
WO2017170615A1 (ja) * 2016-03-29 2017-10-05 三菱化学株式会社 正帯電用電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01166052A (ja) * 1987-12-22 1989-06-29 Toshiba Corp 電子写真感光体
JPH0833661B2 (ja) * 1988-10-31 1996-03-29 松下電器産業株式会社 光導電材料
JPH03134670A (ja) * 1989-10-19 1991-06-07 Toray Ind Inc 電子写真感光体
JP3258397B2 (ja) * 1992-10-05 2002-02-18 コニカ株式会社 感光体の製造方法および電子写真感光体
CN1132863A (zh) * 1994-09-01 1996-10-09 富士电机株式会社 电子照像光敏材料
JPH08123055A (ja) * 1994-09-01 1996-05-17 Fuji Electric Co Ltd 電子写真感光体
JPH0895278A (ja) * 1994-09-20 1996-04-12 Ricoh Co Ltd 電子写真感光体及びこれを用いた電子写真装置
JPH09269605A (ja) * 1996-04-01 1997-10-14 Fuji Electric Co Ltd 電子写真用有機感光体
JPH10104860A (ja) * 1996-08-08 1998-04-24 Canon Inc 電子写真感光体、該電子写真感光体を有するプロセスカートリッジ及び電子写真装置
EP0823668B1 (en) * 1996-08-08 2002-11-13 Canon Kabushiki Kaisha Electrophotographic photosensitive member, and process cartridge and electrophotographic apparatus utilizing the same
JPH10115941A (ja) * 1996-10-14 1998-05-06 Fuji Electric Co Ltd 電子写真感光体
JP2002072520A (ja) * 2000-09-01 2002-03-12 Fuji Denki Gazo Device Kk 電子写真用感光体およびその製造方法
JP4137396B2 (ja) * 2001-03-07 2008-08-20 株式会社リコー 電子写真感光体及びこれを用いた電子写真装置
JP4082875B2 (ja) * 2001-03-26 2008-04-30 株式会社リコー 電子写真感光体及び画像形成装置
JP2004226637A (ja) * 2003-01-22 2004-08-12 Kyocera Mita Corp 単層型電子写真感光体およびそれを有する画像形成装置
US7919219B2 (en) * 2004-11-24 2011-04-05 Hodogaya Chemical Co., Ltd. Electrophotographic photosensitive body
JP4823124B2 (ja) * 2007-03-30 2011-11-24 山梨電子工業株式会社 単層分散型感光体、電子写真装置
US8268520B2 (en) * 2010-05-26 2012-09-18 Xerox Corporation Polyalkylene glycol benzoate polytetrafluoroethylene containing photoconductors
JP5194057B2 (ja) * 2010-06-04 2013-05-08 京セラドキュメントソリューションズ株式会社 正帯電単層型電子写真感光体、及び画像形成装置
JP5991936B2 (ja) * 2013-02-27 2016-09-14 京セラドキュメントソリューションズ株式会社 正帯電単層型電子写真感光体、及び画像形成装置

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6593047B2 (en) * 2000-08-31 2003-07-15 Kyocera Mita Corporation Single-layer type electrophotosensitive material
US7195851B2 (en) * 2001-03-30 2007-03-27 Yamanashi Electronics Co., Ltd. Charge-transfer material and process for producing the same, electron-transfer agent, photoreceptor for electrophotography and organic electroluminescence element using said charge-transfer material
US20030211413A1 (en) * 2002-05-10 2003-11-13 Xerox Corporation. Imaging members
US20060183044A1 (en) * 2005-02-16 2006-08-17 Samsung Electronics Co., Ltd. Electrophotographic photoreceptor containing asymmetric naphthalenetetracarboxylic acid diimide derivatives and electrophotographic imaging apparatus employing the same
JP2011170041A (ja) * 2010-02-17 2011-09-01 Mitsubishi Chemicals Corp 電子写真感光体、電子写真感光体カートリッジ及び画像形成装置
WO2017170615A1 (ja) * 2016-03-29 2017-10-05 三菱化学株式会社 正帯電用電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Diamond, A. (ed.) Handbook of Imaging Materials. New York: Marcel-Dekker, Inc. pp. 145-164. (Year: 2001) *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11287756B2 (en) 2017-03-01 2022-03-29 Mitsubishi Chemical Corporation Positive charging electrophotographic photoreceptor, electrophotographic cartridge and image forming apparatus

Also Published As

Publication number Publication date
WO2016148035A1 (ja) 2016-09-22
CN107407895B (zh) 2021-03-16
JP2016170408A (ja) 2016-09-23
CN107407895A (zh) 2017-11-28
JP6662111B2 (ja) 2020-03-11

Similar Documents

Publication Publication Date Title
JP4354969B2 (ja) 電子写真感光体及び画像形成装置
JP2016095513A (ja) 電子写真感光体、及び画像形成装置
JP2013257416A (ja) 電子写真感光体、それを備えた画像形成装置およびプロセスカートリッジ
US20180004101A1 (en) Single-layer type electrophotographic photoreceptor for positive charging, electrophotographic photoreceptor cartridge, and image forming apparatus
JP6741165B2 (ja) 電子写真用感光体、その製造方法および電子写真装置
JP4735421B2 (ja) 電子写真感光体、プロセスカートリッジ、および画像形成装置
JP6107298B2 (ja) 電子写真感光体、電子写真プロセスカートリッジ及び画像形成装置
JP2007147824A (ja) 電子写真感光体及び画像形成装置
JP2008083105A (ja) 電子写真感光体、画像形成装置用プロセスカートリッジ及び画像形成装置
JP2006195476A (ja) 電子写真感光体，電子写真カートリッジ及び電子写真画像の形成装置
CN107111258B (zh) 电子照相感光体、电子照相感光体盒和图像形成装置
JP4466414B2 (ja) 電子写真感光体、該感光体を用いた画像形成装置、およびカートリッジ
JP5655490B2 (ja) 電子写真感光体、該感光体を用いた画像形成装置、および電子写真カートリッジ
JP5309465B2 (ja) 電子写真感光体及び画像形成装置
JP6617663B2 (ja) 電子写真感光体、画像形成装置、及びプロセスカートリッジ
JP6331630B2 (ja) 電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置
JP2014167555A (ja) 電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置
JP6641969B2 (ja) 電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置
JP2001066800A (ja) 電子写真感光体、電子写真プロセスカートリッジ、及び電子写真装置
JP5556327B2 (ja) 電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置
JP5772264B2 (ja) 電子写真感光体、電子写真カートリッジ及び画像形成装置
JP2006251328A (ja) 電子写真感光体、プロセスカートリッジ及び電子写真装置
JP6102639B2 (ja) 電子写真感光体、電子写真カートリッジ、及び画像形成装置
JP2015191167A (ja) 電子写真感光体、電子写真感光体カートリッジ、及び画像形成装置
JP2016138936A (ja) 電子写真感光体、電子写真プロセスカートリッジ、及び画像形成装置

Legal Events

Date Code Title Description
AS Assignment

Owner name: MITSUBISHI CHEMICAL CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WADA, MITSUO;FUCHIGAMI, HIROE;ANDO, AKIRA;REEL/FRAME:043565/0471

Effective date: 20170911

STPP Information on status: patent application and granting procedure in general

Free format text: ADVISORY ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION